POLAR Neutron Detectors

The National Institute of Standards and Technology seeks eighty-five neutron proportional counters for its POLAR spectrometer instrument, with proposals due August 17. The procurement carries no set-aside and is open to competitive bidding.

Place of performance is Gaithersburg, Maryland. The counters must be new, with 8 mm outer diameter and 150 mm active length, stainless steel tube bodies, flying lead anode connections of at least 610 mm, and 90% target sensitivity for 5 meV neutrons using 3He detection gas with CO2 and Ar quench gases. Detectors must operate across neutron flux levels from 10^-2 to 10^4 neutrons/second while maintaining linear response at maximum flux, withstand sustained neutron fluence of 10^3 neutrons/second over twenty years, and perform at ambient temperature to 85°F, atmospheric pressure, in air. Amendment 0001 extended lead time from four months to fifty-two weeks after receipt of order. Amendment 0002 clarified that active length may be shortened by no more than 10% if necessary, and that no specific Quality Assurance certification is required. Amendment 0003, issued August 14, confirmed that vendors may select quench gas mixtures (CO2 and Ar or CO2 alone) and their partial pressures provided performance parameters are met, and clarified detector efficiency and dark count rate expectations.

Contractor must submit firm-fixed price quotation with design drawings, bill of materials with lead times, cutsheets, specifications, wiring diagrams, and manuals for approval prior to manufacturing. Deliverables include contractor point of contact within one week of award, design drawings within three weeks, bill of materials within two weeks after design acceptance, and all counters no later than four months after order receipt. Delivery is FOB Destination with contractor bearing shipping costs. Contractor provides one-year manufacturer warranty covering parts and labor commencing upon government acceptance. Payment is made within thirty days of receipt and acceptance of invoices submitted after system acceptance. NAICS is 334516, Analytical Laboratory Instrument Manufacturing; PSC is 6640, Laboratory Equipment and Supplies. Contract incorporates FAR provisions including Buy American requirements and standard payment procedures through the Treasury Invoice Processing Platform.